Improvement in steam-engine valves



VA w. HARRIS. Improvement in Steam Engine-Valves. No. 124,817. IPatented Marchl9,1872.

NITED S'rA'rEs rrrcn.

ABRAHAM w. HARRIs, or PROVIDENCE, RHoDE isnAnn.

IMPROVEMENT IN STEAM-ENGINE VALVES.

Specification forming part of Letters Patent No. 124,817, dated March19, 1872.

- inal vertical section, showing valve about to open. Fig. 3 is ahorizontal section of Fig. 2 on line AB. Fig. 4 is a vertical sectionthrough lower box. Fig. 5 is vertical section through lower box, showingvalve open. Fig. 6 is a horizontal section of Fig. 5 on line B C. Fig. 7is a bottom view of upper valve, showing slot. Fig. 8 is a bottom viewof lower valve, showing slot. Fig. 9 is a long vertical section throughcylinder, &c., of engine, showing valves in position.

The object of my invention is to so construct the valves and their seatsthat the ridges usually formed upon their wearing-surfacesby theconstant action of the former will. be entirely avoided; and consists inthe recessing of the steam and exhaust valves and their seats, in themanner hereinafter described.

To illustrate my invention I will take the construction of the inductionand eduction valves of the Corliss engine and their seats.

These valves are four in number, the two at the top of the cylinderbeing the steam-valves, and

serving both as induction and cut-off valves,

connect them with the wrist-plate, motion being imparted to thewrist-plate by the eccen-.

trio. I It is well understood that the constant forward and backwardmotion of the valves upon their seats will in a short time, by wearingaway that portion of the seats over which they actually pass, leave atthe points where their movements cease a ridge upon the seat, as well asupon the valve at a point in its wearing-surface near the opening edgeof the port.

These ridges make it necessary to turn off the valves and bore out theseats whenever it is desired to alter the connections-such alterationsinvolving much delay and expenseotherwise the valves will be thrown upby these ridges and separated from their seats, thus allowing the steamto blow under, the efl'ect of which it is not necessary for me todescribe.

My invention, which is particularly adapted to what is known as theCorliss engine, and in connection with which 1 will now proceed todescribe it,is intended to provide against the possibility of wearingridges upon the valves or seats, and, consequently, the unsatisfactoryresults arising therefrom.

In the drawing, Figures 1, 2, 3, and 7, which represent the steam orinduction valves, A is the valve-box, B the valve, C the valve-seat, andD the port. The valve B is constructed with a recess, E, running theentire length of the port, and-the valve-seat C with two recesses, F andF, both running its entire length.

The operation of this portion of my invention is as follows: Commencingwith the valve B closed, as shown in Fig. 1, it will be seen that, as itmoves toward the position indicated by the dotted lines and opens theport, it will, before reaching its extreme throw in that direction, runoff its seat a portion of its width and overlap the recess F; and again,upon resuming its former position, it will run off and also. overlap aportion of the recess F; at the same time the recess E of the valve willoverlap the opening edge of the port D.

In Figs. 4., 5, 6, and 8, which represent the exhaust or eductionvalves, G is the valve, H the seat, and I and J the ports. The valve Gis provided with a recess, K, and the valveseat with two recesses, L andM.

The operation of this portion of my invention is as follows: Commencingwith the valve closed, as shown in Fig. 4, it will be seen that therecess K in the valve Gr overlaps the opening edge of the port I; andwhen the valve has attained its extreme throw in the opposite direction,as shown in Fig. 5, it will be found that the valve has run off its seatand slightly overlaps the recess L and again, upon its resuming itsformer position, as shown in Fig. 4, it will run off and overlap aportion of the recess M.

Thus, by recessing the valves and seats, as herein described, so thatthe valves at their extreme throw each way will run off their seats, theformation of ridges is eflectually prevented.

What I claim as my invention and desire to secure by Letters Patent, is-

I claim as my invention the Within-described recesses in the valves andvalve-seats of steamengines, which conjointly operate with each othersubstantially as and for the purpose set forth.

ABRAHAM W. HARRIS.

Witnesses:

WALTER B. VINCENT, JOHN D. W. TAYLOR.

